20516521273 has 2 divisors, whose sum is σ = 20516521274. Its totient is φ = 20516521272.

The previous prime is 20516521253. The next prime is 20516521331. The reversal of 20516521273 is 37212561502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20337041664 + 179479609 = 142608^2 + 13397^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516521273 - 2⁵ = 20516521241 is a prime.

It is not a weakly prime, because it can be changed into another prime (20516521253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258260636 + 10258260637.

It is an arithmetic number, because the mean of its divisors is an integer number (10258260637).

Almost surely, 2^20516521273 is an apocalyptic number.

It is an amenable number.

20516521273 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516521273 is an equidigital number, since it uses as much as digits as its factorization.

20516521273 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 34.

The spelling of 20516521273 in words is "twenty billion, five hundred sixteen million, five hundred twenty-one thousand, two hundred seventy-three".